Dual Lumen Cannula with Adjustable Length Infusion Tube

ABSTRACT

A dual lumen coaxial cannula assembly including a first infusion tube having a proximal end, a distal end, and a sidewall extending circumferentially therebetween, as well as a second drainage tube co-axially aligned with the first infusion tube, the second drainage tube having a proximal end, a distal end, and a sidewall extending circumferentially therebetween. The assembly also includes a connector assembly, which has an inlet portion through which a portion of the first infusion tube is configured to extend and an outlet portion through which a portion of the second drainage tube is configured to extend. The connector assembly is configured to enable selective axial displacement of the first infusion tube through the second drainage tube.

BACKGROUND Field

The present disclosure generally relates to devices and methods forassisting a patient's heart with a cannula. More specifically, thepresent disclosure is related to a dual lumen cannula assembly having anadjustable length infusion tube, as well as to methods for assisting apatient's heart with a cannula assembly.

Description of the Related Art

Traditional cannulae used for patient life support generally involvesingle lumen cannulae at multiple insertion sites, high volume circuits,and cannulae that are not capable of long-term use. Multiple insertionsites increase the risk of bleeding, vessel damage, and infection, aswell as pain and discomfort to the patient. These cannulae are designedand built for short-term acute therapies. Additionally, traditionalcannulae usually require access sites located in the patient's groinarea near the right or left femoral veins.

While multi-lumen cannula assemblies exist in the art in order to avoidthe need for multiple insertion sites, the infusion tube and thedrainage tube of these cannula assemblies are generally fixed in lengthrelative to one another, as the infusion tube is affixed to the assemblyby way of, e.g., an adhesive. This fixed length of the infusion tuberelative to the drainage tube may limit the adjustability of cannulaassembly placement within the patient's body, thereby making itdifficult for the user to account for differences in patient size and/orpatient vessel length when positioning the cannula assembly.

Examples of existing cannula devices are described in U.S. Pat. Nos.9,168,352, 9,782,534, and 10,279,101, the disclosures of which arehereby incorporated by reference in their entireties.

SUMMARY

In view of the foregoing, there exists a need for a dual lumen cannulacapable of enabling adjustability in the length of an inner infusiontube relative to the outer drainage tube.

Embodiments of the present disclosure are directed to a dual lumencoaxial cannula assembly. The assembly includes a first infusion tubehaving a first elongate body defining a first lumen therethrough, thefirst infusion tube having a proximal end, a distal end, and a sidewallextending circumferentially therebetween. The assembly also includes asecond drainage tube co-axially aligned with the first infusion tube andhaving a second elongate body with a second lumen defined by a spacebetween the first infusion tube and second drainage tube, the seconddrainage tube having a proximal end, a distal end, and a sidewallextending circumferentially therebetween. The assembly further includesa connector assembly, wherein the connector assembly includes an inletportion through which a portion of the first infusion tube is configuredto extend and outlet portion through which a portion of the seconddrainage tube is configured to extend. Additionally, the connectorassembly is configured to enable selective axial displacement of thefirst infusion tube through the second drainage tube.

In some embodiments, the connector assembly includes a first valvepositioned circumferentially around a portion of the first infusion tubeto secure the first infusion tube relative to the connector assembly.

In some embodiments, the first valve is configured as a passive valve.

In some embodiments, the first valve is an O-ring.

In some embodiments, the connector assembly includes a second valvepositioned circumferentially around another portion of the firstinfusion tube to secure the first infusion tube relative to theconnector assembly.

In some embodiments, the second valve is configured as an active valve.

In some embodiments, the second valve is a Tuohy-Borst valve.

In some embodiments, the second valve includes at least one sensorconfigured to provide feedback regarding the securement of the firstinfusion tube relative to the second valve.

In some embodiments, the at least one sensor includes at least one of apressure transducer and an axial force strain gauge.

In some embodiments, the assembly further includes a side-portconnection positioned between the first valve and the second valve ofthe connector assembly.

In some embodiments, the assembly further includes an embolic protectiondevice positioned between the first valve and the second valve of theconnector assembly.

In some embodiments, the first infusion tube includes at least a firstmagnet of a first polarity and a second magnet of the first polaritypositioned along the first elongate body, and further wherein the seconddrainage tube comprises a third magnet of a second polarity positionedproximate to a distal end thereof.

In some embodiments, the first magnet is positioned to represent adistal length limit of the first infusion tube and the second magnet ispositioned to represent a proximal length limit of the first infusiontube.

In some embodiments, the assembly further includes at least oneintermediate magnet positioned between the first magnet and the secondmagnet on the first infusion tube.

In some embodiments, the first infusion tube includes a plurality ofinfusion apertures provided at the distal end, the infusion aperturesextending through the sidewall of the first infusion tube.

In some embodiments, the second drainage tube includes a plurality ofdrainage apertures provided at the distal end, the drainage aperturesextending through the sidewall of the second drainage tube.

Other embodiments of the present disclosure are directed to a method ofassisting a patient's heart. The method includes providing a dual lumencoaxial cannula assembly including a first infusion tube having a firstelongate body defining a first lumen therethrough, the first infusiontube having a proximal end, a distal end, and a sidewall extendingcircumferentially therebetween, a second drainage tube co-axiallyaligned with the first infusion tube and having a second elongate bodywith a second lumen defined by a space between the first infusion tubeand second drainage tube, the second drainage tube having a proximalend, a distal end, and a sidewall extending circumferentiallytherebetween, and a connector assembly, wherein the connector assemblycomprises an inlet portion through which a portion of the first infusiontube is configured to extend and outlet portion through which a portionof the second drainage tube is configured to extend. The connectorassembly is configured to enable selective axial displacement of thefirst infusion tube through the second drainage tube. The method furtherincludes inserting the dual lumen coaxial cannula into an internaljugular vein of the patient, the dual lumen coaxial cannula having alength to extend from the patient's neck area to the patient's heart.The method includes maneuvering the dual lumen coaxial cannula throughthe patient's vasculature such that the first distal end of the firstinfusion tube is at least within proximity of the patient's pulmonaryartery and such that the second distal end of the second drainage tubeis at least within proximity of the patient's right atrium. The methodalso includes adjusting an axial position of the first distal end of thefirst infusion tube relative to the second distal end of the seconddrainage tube. The method includes securing the first infusion tube in aselected axial position relative to the second drainage tube. The methodfurther includes connecting the dual lumen coaxial cannula to a bloodpump for establishing right ventricular support.

In some embodiments, securing the first infusion tube in the selectedaxial position includes tightening a valve around a portion of the firstinfusion tube, wherein the valve is positioned on the connectorassembly.

In some embodiments, the method further includes providing at least afirst magnet of a first polarity and a second magnet of the firstpolarity along the first elongate body of the first infusion tube, andproviding a third magnet of a second polarity proximate to a distal endof the second drainage tube, wherein the first magnet and the secondmagnet provide tactile feedback regarding a position of the firstinfusion tube relative to the third magnet of the second drainage tube.

In some embodiments, blood from the blood pump is delivered to thepatient's pulmonary artery through a plurality of infusion apertures ofthe first infusion tube, and blood is withdrawn from the patient's rightatrium through a plurality of drainage apertures of the second drainagecannula.

Further embodiments of the present disclosure are set forth in thefollowing numbered clauses.

Clause 1. A dual lumen coaxial cannula assembly comprising: a firstinfusion tube having a first elongate body defining a first lumentherethrough, the first infusion tube having a proximal end, a distalend, and a sidewall extending circumferentially therebetween; a seconddrainage tube co-axially aligned with the first infusion tube and havinga second elongate body with a second lumen defined by a space betweenthe first infusion tube and second drainage tube, the second drainagetube having a proximal end, a distal end, and a sidewall extendingcircumferentially therebetween; and a connector assembly, wherein theconnector assembly comprises an inlet portion through which a portion ofthe first infusion tube is configured to extend and outlet portionthrough which a portion of the second drainage tube is configured toextend, wherein the connector assembly is configured to enable selectiveaxial displacement of the first infusion tube through the seconddrainage tube.

Clause 2. The dual lumen coaxial cannula assembly of clause 1, whereinthe connector assembly comprises a first valve positionedcircumferentially around a portion of the first infusion tube to securethe first infusion tube relative to the connector assembly.

Clause 3. The dual lumen coaxial cannula assembly of clause 2, whereinthe first valve is configured as a passive valve.

Clause 4. The dual lumen coaxial cannula assembly of clause 3, whereinthe first valve is an O-ring.

Clause 5. The dual lumen coaxial cannula assembly of clause 2, whereinthe connector assembly comprises a second valve positionedcircumferentially around another portion of the first infusion tube tosecure the first infusion tube relative to the connector assembly.

Clause 6. The dual lumen coaxial cannula assembly of clause 5, whereinthe second valve is configured as an active valve.

Clause 7. The dual lumen coaxial cannula assembly of clause 6, whereinthe second valve is a Tuohy-Borst valve.

Clause 8. The dual lumen coaxial cannula assembly of clause 5, whereinthe second valve comprises at least one sensor configured to providefeedback regarding the securement of the first infusion tube relative tothe second valve.

Clause 9. The dual lumen coaxial cannula assembly of clause 8, whereinthe at least one sensor comprises at least one of a pressure transducerand an axial force strain gauge.

Clause 10. The dual lumen coaxial cannula assembly of clause 5, furthercomprising a side-port connection positioned between the first valve andthe second valve of the connector assembly.

Clause 11. The dual lumen coaxial assembly of clause 5, furthercomprising an embolic protection device positioned between the firstvalve and the second valve of the connector assembly.

Clause 12. The dual lumen coaxial assembly of clause 1, wherein thefirst infusion tube comprises at least a first magnet of a firstpolarity and a second magnet of the first polarity positioned along thefirst elongate body, and further wherein the second drainage tubecomprises a third magnet of a second polarity positioned proximate to adistal end thereof.

Clause 13. The dual lumen coaxial assembly of clause 12, wherein thefirst magnet is positioned to represent a distal length limit of thefirst infusion tube and the second magnet is positioned to represent aproximal length limit of the first infusion tube.

Clause 14. The dual lumen coaxial assembly of clause 12, furthercomprising at least one intermediate magnet positioned between the firstmagnet and the second magnet on the first infusion tube.

Clause 15. The dual lumen coaxial cannula assembly of clause 1, whereinthe first infusion tube includes a plurality of infusion aperturesprovided at the distal end, the infusion apertures extending through thesidewall of the first infusion tube.

Clause 16. The dual lumen coaxial cannula assembly of clause 1, whereinthe second drainage tube includes a plurality of drainage aperturesprovided at the distal end, the drainage apertures extending through thesidewall of the second drainage tube.

Clause 17. A method of assisting a patient's heart, comprising the stepsof: providing a dual lumen coaxial cannula assembly comprising: a firstinfusion tube having a first elongate body defining a first lumentherethrough, the first infusion tube having a proximal end, a distalend, and a sidewall extending circumferentially therebetween, a seconddrainage tube co-axially aligned with the first infusion tube and havinga second elongate body with a second lumen defined by a space betweenthe first infusion tube and second drainage tube, the second drainagetube having a proximal end, a distal end, and a sidewall extendingcircumferentially therebetween, and a connector assembly, wherein theconnector assembly comprises an inlet portion through which a portion ofthe first infusion tube is configured to extend and outlet portionthrough which a portion of the second drainage tube is configured toextend, wherein the connector assembly is configured to enable selectiveaxial displacement of the first infusion tube through the seconddrainage tube; inserting the dual lumen coaxial cannula into an internaljugular vein of the patient, the dual lumen coaxial cannula having alength to extend from the patient's neck area to the patient's heart;maneuvering the dual lumen coaxial cannula through the patient'svasculature such that the first distal end of the first infusion tube isat least within proximity of the patient's pulmonary artery and suchthat the second distal end of the second drainage tube is at leastwithin proximity of the patient's right atrium; adjusting an axialposition of the first distal end of the first infusion tube relative tothe second distal end of the second drainage tube; securing the firstinfusion tube in a selected axial position relative to the seconddrainage tube; and connecting the dual lumen coaxial cannula to a bloodpump for establishing right ventricular support.

Clause 18. The method of clause 17, wherein securing the first infusiontube in the selected axial position comprises tightening a valve arounda portion of the first infusion tube, wherein the valve is positioned onthe connector assembly.

Clause 19. The method of clause 17, further comprising providing atleast a first magnet of a first polarity and a second magnet of thefirst polarity along the first elongate body of the first infusion tube,and providing a third magnet of a second polarity proximate to a distalend of the second drainage tube, wherein the first magnet and the secondmagnet provide tactile feedback regarding a position of the firstinfusion tube relative to the third magnet of the second drainage tube.

Clause 20. The method of clause 17, wherein blood from the blood pump isdelivered to the patient's pulmonary artery through a plurality ofinfusion apertures of the first infusion tube, and further wherein bloodis withdrawn from the patient's right atrium through a plurality ofdrainage apertures of the second drainage cannula.

Further details and advantages of the present disclosure will beunderstood from the following detailed description read in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of one embodiment of a coaxial cannula shown witha Y-shaped connector in accordance with an aspect of the presentdisclosure;

FIG. 2 is a perspective view of the Y-shaped connector shown coupled tothe coaxial cannula of FIG. 1;

FIG. 3 is a partial perspective view of the Y-shaped connector inaccordance with another aspect of the present disclosure;

FIG. 4 is another side view of the coaxial cannula with the Y-shapedconnector in accordance with an aspect of the present disclosure;

FIG. 5 is a schematic view of one embodiment of a coaxial cannulapositioned inside a patient's heart; and

FIG. 6 is a schematic view of the coaxial cannula of any of FIGS. 1-4positioned inside a patient's heart.

DETAILED DESCRIPTION

For purposes of the description hereinafter, the terms “end,” “upper,”“lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,”“lateral,” “longitudinal,” and derivatives thereof shall relate to theinvention as it is oriented in the drawing figures. However, it is to beunderstood that the invention may assume various alternative variationsand step sequences, except where expressly specified to the contrary. Itis also to be understood that the specific devices and processesillustrated in the attached drawings, and described in the followingspecification, are simply exemplary embodiments or aspects. Hence,specific dimensions and other physical characteristics related to theembodiments or aspects disclosed herein are not to be considered aslimiting.

As used herein, the term “at least one of” is synonymous with “one ormore of”. For example, the phrase “at least one of A, B, and C” meansany one of A, B, and C, or any combination of any two or more of A, B,and C. For example, “at least one of A, B, and C” includes one or moreof A alone; or one or more B alone; or one or more of C alone; or one ormore of A and one or more of B; or one or more of A and one or more ofC; or one or more of B and one or more of C; or one or more of all of A,B, and C. Similarly, as used herein, the term “at least two of” issynonymous with “two or more of”. For example, the phrase “at least twoof D, E, and F” means any combination of any two or more of D, E, and F.For example, “at least two of D, E, and F” includes one or more of D andone or more of E; or one or more of D and one or more of F; or one ormore of E and one or more of F; or one or more of all of D, E, and F.

When used in relation to a cannula, catheter, or other device insertedinto a patient, the term “proximal” refers to a portion of such devicefarther from the end of the device inserted into the patient. When usedin relation to a cannula, catheter, or other device inserted into apatient, the term “distal” refers to a portion of such device nearer tothe end of the device inserted into the patient.

Referring to the drawings, in which like reference characters refer tolike parts throughout the several views thereof, various embodiments ofa coaxial, dual lumen cannula 10 (hereinafter referred to as “coaxialcannula 10”) are shown. With initial reference to FIG. 1, the assembledcoaxial cannula 10, according to one embodiment, generally includes afirst infusion tube 12 and a second drainage tube 14, with the firstinfusion tube 12 configured to pass through the second drainage tube 14.As will be described in further detail hereinbelow, the length of thefirst infusion tube 12 relative to the length of the second drainagetube 14 is configured to be adjustable so as to account for patient sizeand/or patient vessel length.

The first infusion tube 12 is disposed within the second drainage tube14 in a coaxial arrangement centered about a central axis 16. Each ofthe first infusion tube 12 and the second drainage tube 14 has a firstcircumference defining a first lumen and a second circumference defininga second lumen, respectively. The first circumference of the firstinfusion tube 12 is smaller than the second circumference of the seconddrainage tube 14 such that the first infusion tube 12 may be placedwithin the second lumen of the second drainage tube 14. One or both ofthe first infusion tube 12 and the second drainage tube 14 may bemanufactured from a medical-grade material such as polyurethane.Alternatively, the tubes may be made from PVC or silicone, and may bedip molded, extruded, co-molded, or made using any other suitablemanufacturing technique.

The coaxial cannula 10 has sufficient placement flexibility adapted forplacement of the coaxial cannula 10 within a patient's body. Desirably,a vascular insertion site is provided at the internal jugular vein onthe patient's neck area. The coaxial cannula 10 is adapted for placementabove or below the right atrium of the patient's heart. The coaxialcannula 10 may be used with an introducer to guide the placement of thecoaxial cannula 10 as it is inserted within the patient's body.

With continuing reference to FIG. 1, the coaxial cannula 10 is designedto withdraw blood directly from the patient's heart and return bloodback into the patient's heart. The function of the first infusion tube12 is to deliver blood into the blood stream of the patient, while thefunction of the second drainage tube 14 is to drain the blood from thepatient's bloodstream as will be described hereafter.

A plurality of infusion apertures 18 are provided near a distal end ofthe first infusion tube 12, and the distal end of the infusion tubeincludes an infusion opening 19. The plurality of infusion apertures 18are desirably arranged in a circular pattern extending around the outercircumference of the first infusion tube 12. In some embodiments, theplurality of infusion apertures 18 may be disposed in multiple groupsprovided at various sites on the first infusion tube 12. Similarly, thesecond drainage tube 14 includes a plurality of drainage apertures 20provided at a distal end of the second drainage tube 14. The pluralityof drainage apertures 20 are desirably arranged in a circular patternextending around the outer circumference of the second drainage tube 14.In alternative embodiments, the plurality of drainage apertures 20 maybe arranged in groups disposed at various sites along the length of thesecond drainage tube 14.

The infusion apertures 18 are separated from the drainage apertures 20by a variable distance D. In different embodiments of the coaxialcannula 10, the separation of infusion apertures 18 from drainageapertures 20 determines the amount of mixing of oxygenated blood andunoxygenated blood. As will be described in further detail below, thedistance D may be varied by user adjustment of first infusion tube 12with respect to the second drainage tube 14 along the central axis 16.The user may axially displace (i.e., push or pull) the first infusiontube 12 through the second drainage tube 14 until an acceptable anddesired distance D is attained. In this way, the distance D may bealtered based on, e.g., the age and/or size of the patient, as well asthe desired flow rates during the medical procedure where the coaxialcannula 10 is used. For example, a distance D may be varied between 5 cmand 30 cm. More specifically, in some embodiments, the distance D may bevaried between 8 cm and 28 cm. However, it is to be understood that thedistance D is not limited to these lengths, and may be varied betweenlengths lesser or greater than those described herein.

With continuing reference to FIG. 1, a Y-shaped connector assembly 22 isprovided at the proximal end of the coaxial cannula 10. Portions of theY-shaped connector assembly 22 may be made substantially frompolycarbonate as an example, but could also be made from PVC, acrylic,or polyurethane. The Y-shaped connector assembly 22 may be constructedusing one or more manufacturing techniques including injection molding,machining, or dip forming. One of ordinary skill in the art willunderstand that a variety of other manufacturing techniques may be usedfor constructing the Y-shaped connector assembly 22 without departingfrom the intended scope of the invention. Additionally, while aconnector assembly 22 is shown and described herein as being Y-shaped,it is to be understood that connector assembly 22 may be formed in othershapes and configurations.

The Y-shaped connector assembly 22 includes an inlet portion 24 in fluidcommunication with the first infusion tube 12 to transfer blood from ablood pump (not shown) to the first infusion tube 12. An outlet portion26 of the Y-shaped connector assembly 22 is in fluid communication withthe second drainage tube 14 to transfer blood from the second drainagetube 14 to the blood pump. The outlet portion 26 and the inlet portion24 of the Y-shaped connector assembly 22 are arranged such that thefluid pathways leading from the second drainage tube 14 and to the firstinfusion tube 12 transition from a coaxial arrangement at a distal endof the Y-shaped connector assembly 22 to an axially-offset arrangementat a proximal end of the Y-shaped connector assembly 22.

Referring to FIG. 2, the details of Y-shaped connector assembly 22 andthe coupling of coaxial cannula 10 with Y-shaped connector assembly 22are shown. As described above, the first infusion tube 12 is configuredto extend through inlet portion 24 of Y-shaped connector assembly 22,while the outlet portion 26 acts as the fluid pathway for seconddrainage tube 14. The first infusion tube 12 is configured to be capableof user-controlled axial displacement through inlet portion 24 in boththe distal and proximal directions. That is, the user may feed the firstinfusion tube 12 through the inlet portion 24 and the second drainagetube 14 in the distal direction, thereby increasing the length of thefirst infusion tube 12 relative to the distal end of the second drainagetube 14. Conversely, if the user pulls the first infusion tube 12 in theproximal direction, the length of the first infusion tube 12 relative tothe distal end of the second drainage tube 14 decreases. Accordingly,the Y-shaped connector assembly 22 and coaxial cannula 10 enables useradjustment of the length of the first infusion tube 12 relative to thesecond drainage tube 14.

In one embodiment, the first infusion tube 12 includes a first helicalcoil 60 extending through at least a portion of the length thereof,while the second drainage tube 14 includes a second helical coil 46extending through at least a portion of the length thereof. The firsthelical coil 60 and/or the second helical coil 46 may be manufacturedfrom medical-grade metal or plastic and may act to minimize kinkingand/or collapse of the first infusion tube 12 and/or the second drainagetube 14.

In addition to serving as a junction for the first infusion tube andsecond drainage tube 14 to form coaxial cannula 10, the Y-shapedconnector assembly 22 further includes a valve system configured to bothcontrol movement of first infusion tube 12 and enable blood managementby, e.g., minimizing thrombus formation, controlling blood loss, etc.

Specifically, as shown in FIG. 2, Y-shaped connector assembly 22includes a distal valve 28 located at or near the location where inletportion 24 and outlet portion 26 meet to form a common lumen portion 29.The distal valve 28 is positioned and configured to provide a smoothtransition between the inlet portion 24 and the common lumen portion 29of Y-shaped connector assembly 22, thereby minimizing blood flowdisruption and potential thrombus formation due to such blood flowdisruption.

Additionally, distal valve 28 is configured to at least partially securethe first infusion tube 12 relative to the Y-shaped connector assembly22, while still allowing for selective axial movement of the firstinfusion tube 12 through the Y-shaped connector assembly 22 and thesecond drainage tube 14. For example, in one embodiment, distal valve 28is configured to function passively as an O-ring, wherein the opening ofthe O-ring is slightly smaller in diameter than the outer diameter offirst infusion tube 12. The O-ring may be formed of any appropriatemedical grade material such as, e.g., polyurethane, PVC, or silicone. Inthis way, the O-ring forming distal valve 28 provides a friction fitover the outer diameter of first infusion tube 12, both securing thefirst infusion tube 12 and preventing blood to flow past distal valve28, thereby mitigating thrombus formation, blood loss, etc. However, thefriction fit of the distal valve 28 is configured to allow axialmovement of first infusion tube 12 upon user-directed force on the firstinfusion tube 12, thereby allowing the overall length of first infusiontube 12 to be adjusted relative to second drainage tube 14, as describedabove.

Alternatively, in another embodiment, and in lieu of a passiveconfiguration, distal valve 28 may be configured as an active valveincorporating, e.g., a dial or button (not shown) located outside of theY-shaped connector assembly for manipulation by the user in order toselectively secure and/or release the first infusion tube 12.

Referring still to FIG. 2, in addition to distal valve 28, Y-shapedconnector assembly 22 may further include a second, proximal valve 30positioned along the inlet portion 24. Proximal valve 30 is configuredto provide redundancy and a factor of safety with respect to securementof first infusion tube 12, working in conjunction with distal valve 28to secure first infusion tube 12 in place once the user has positionedthe first infusion tube 12 at a desired length relative to seconddrainage tube 14.

In one embodiment, proximal valve 30 is a manually activated valve suchas, e.g., a Tuohy-Borst valve. Accordingly, proximal valve 30 includes arotatable cap 34, which surrounds the first infusion tube 12. If theuser rotates the cap 34 in a clockwise direction, an inner ring (notshown) of the proximal valve 30 compresses along the outer surface ofthe first infusion tube 12, thereby acting to secure the first infusiontube 12 in place. Conversely, if the user rotates the cap 34 in acounterclockwise direction, the inner ring releases from the outersurface of the first infusion tube 12, thereby allowing first infusiontube 12 to be axially displaced relative to the Y-shaped connectorassembly 22. In this way, the proximal valve 30 may act as the primarymeans for securement of the first infusion tube 12, particularly ifdistal valve 28 is configured as a passive valve (e.g., an O-ring).

In addition to providing securement of the first infusion tube 12, inone embodiment, proximal valve 30 also serves as a secondary source ofblood management within the Y-shaped connector assembly 22. That is,when the inner ring of the proximal valve 30 is tightened around thefirst infusion tube 12 in order to secure first infusion tube 12 priorto use, blood is prevented from traveling through (and potentiallyleaking from) the inlet portion 24 of the Y-shaped connector assembly22. As such, thrombus formation and/or blood loss within the valvesystem of Y-shaped connector assembly 22 is substantially prevented,particularly when proximal valve 30 is utilized in series with distalvalve 28.

The proximal valve 30 may include one or more means for providingpressure or axial force feedback indicative of a sufficient securementand/or seal around the first infusion tube 12. For example, in oneembodiment, the proximal valve 30 includes at least one sensor 36,wherein the at least one sensor 36 is configured to provide feedbackregarding the securement of the proximal valve 30 around the firstinfusion tube 12. In one embodiment, the at least one sensor 36 may beconfigured as a pressure transducer. In another embodiment, the at leastone sensor 36 may be configured as an axial force strain gauge. The atleast one sensor 36 may transmit the feedback relating to securement ofthe first infusion tube 12 to a remote controller and/or user interfacevia either a wired or wireless connection. Alternatively, the proximalvalve 30 may incorporate one or more indicators (e.g., LEDs) capable ofcommunicating the feedback from the at least one sensor 36 to the user.

In another embodiment, in lieu of (or in addition to) the distal valve28 and/or the proximal valve 30, the Y-shaped connector assembly 22 mayinclude a toothed ring (not shown) sized and configured to contact andsurround the first infusion tube 12. The toothed ring includes aplurality of teeth directed radially inward and angled in a distaldirection relative to the Y-shaped connector assembly 22. With thisconfiguration, the toothed ring enables the first infusion tube 12 to beaxially moved/adjusted in the distal direction, as the first infusiontube 12 is able to pass through the opening formed by the plurality ofteeth due to the tooth angulation in the distal direction. However, thetoothed ring is configured to substantially restrict or prevent movementof the first infusion tube 12 in the opposite (i.e., proximal)direction, as such movement causes the plurality of teeth to bend in theproximal direction, thereby reducing the circumference of the passageformed by the toothed ring around the first infusion tube 12, whichcauses the plurality of teeth to “bite” into the outer sidewall of thefirst infusion tube 12. In this way, the toothed ring may provide for atleast supplemental securement of the first infusion tube 12 relative tothe Y-shaped connector assembly 22.

Referring still to FIG. 2, and in accordance with another aspect of thepresent disclosure, Y-shaped connector assembly 22 further includes aside port connection 38 positioned between the distal valve 28 and theproximal valve 30. The side-port connection 38 is configured to enableproper management of the space between the respective valves 28, 30 byway of, e.g., a barb connector accessible to the user. Morespecifically, during initial set-up of the coaxial cannula 10, theside-port connection 38 can be utilized for de-airing the space betweenthe respective valves 28, 30. Additionally and/or alternatively, theside-port connection 38 can be used to establish a heparin lock in thespace between valves 28, 30 in order to minimize or prevent bloodstasis. By injecting heparin, an anti-coagulant, into the space betweenthe valves 28, 30 via the side-port connection 38, blood is able to flowmore smoothly through the space, and potential clotting may be betterprevented. Furthermore, in one embodiment, the side-port connection 38can be used during patient support in order to manage the valve space asneeded to minimize or prevent blood stasis.

Next, referring to FIG. 3, another aspect of the present disclosure withrespect to Y-shaped connector assembly 22 is shown. Specifically, anembolic protection device 40 may be deployed within the valve spacebetween respective valves 28, 30. Embolic protection device 40 may be inthe form of, e.g., a filter or basket capable of capturing a thrombus orclot before the thrombus or clot enters the patient's blood stream. Thatis, if a thrombus or clot were to form in the space between the distalvalve 28 and the proximal valve 30 of Y-shaped connector assembly 22 dueto blood stasis, the embolic protection device 40 serves tosubstantially prevent the thrombus or clot from traveling beyond thevalve space, thereby substantially reducing the risk of an embolicevent. While embolic protection device 40 is shown as a filter or basketin FIG. 3, it is to be understood that embolic protection device 40 maybe any appropriate device capable of filtering. Furthermore, while shownas placed in the space between the distal valve 28 and the proximalvalve 30 in FIG. 3, it is to be understood that embolic protectiondevice 40 may be situated elsewhere in the Y-shaped connector assembly22 and/or the coaxial cannula 10.

With reference to FIG. 4, another aspect of the present disclosure isshown. As described above, the first infusion tube 12 is capable ofaxial adjustment/movement relative to second drainage tube 14. However,in order for the user to establish the desired position of the infusionapertures 18 of the first infusion tube 12 relative to the drainageapertures 20 of the second drainage tube 14 when such axial adjustmentis made with the coaxial cannula 10 within the patient's body, there isa need for the user to receive feedback as to the position of the firstinfusion tube 12. Accordingly, in one embodiment, the coaxial cannula 10may include a plurality of magnets configured to provide incrementaltactile feedback to the user as the first infusion tube 12 is movedthrough the second drainage tube 14.

Specifically, as shown in FIG. 4, the second drainage tube 14 includes afirst magnet 50 having a first polarity positioned at or near a distalend portion 42 thereof. In one embodiment, the first magnet 50 may bering-shaped and may extend circumferentially around (or within) thesidewall of the second drainage tube 14. Alternatively, the first magnet50 may include one or more distinct magnets placed along thecircumference of the second drainage tube 14. The first infusion tube 12includes a second magnet 52, a third magnet 54, a fourth magnet 56, anda fifth magnet 58, with each of magnets 52, 54, 56, 58 having a secondpolarity opposite that of the first polarity of first magnet 50.

In the example shown in FIG. 4, the second magnet 52 is positioned torepresent the distal length limit of first infusion tube 12 (i.e., thegreatest allowable length between the distal end of the first infusiontube 12 and the distal end of the second drainage tube 14), while thethird magnet 54 is positioned to represent the proximal length limit ofthe infusion tube 12 (i.e., the least allowable length between thedistal end of the first infusion tube 12 and the distal end of thesecond drainage tube 14). The distal length limit of the first infusiontube 12, represented by second magnet 52, may be defined to minimizepressure drop and enable the coaxial cannula 10 to achieve blood flowsneeded to provide adequate circulatory support. In some embodiments, themaximum length of first infusion tube 12 may be 75 cm, while the minimumlength of first infusion tube 12 may be 50 cm. However, it is to beunderstood that the maximum and minimum lengths of first infusion tube12 are not limited to the above range.

The fourth magnet 56 and fifth magnet 58 are incrementally positionedbetween the second magnet 52 and the third magnet 54. Similar to thefirst magnet 50, each of magnets 52, 54, 56, 58 may be ring-shaped andmay extend circumferentially around (or within) the sidewall of thefirst infusion tube 12. Alternatively, the magnets 52, 54, 56, 58 mayinclude one or more distinct magnets placed along the circumference ofthe first infusion tube 12. Furthermore, while four total magnets areshown in FIG. 4, it is to be understood that more or fewer magnets maybe utilized.

During use of the coaxial cannula 10 and axial displacement of the firstinfusion tube 12 relative to the second drainage tube 14, the user willreceive tactile feedback as each of the magnets 52, 54, 56, 58 of thefirst infusion tube 12 pass the first magnet 50 of the second drainagetube 14 due to the magnets' opposing polarities. In this way, the userreceives a tactile indication of the precise position of the firstinfusion tube 12 relative to the second drainage tube 14, including theproximal length limit (from third magnet 54) and the distal length limit(from second magnet 52). The magnets 52, 54, 56, 58 may be spaced apartat known increments (e.g., 1 cm) such that the user can preciselyposition and secure the first infusion tube 12 at a desired lengthrelative to the second drainage tube 14.

While the example described with respect to FIG. 4 utilizes magnets toprovide tactile feedback to the user regarding the positioning of thefirst infusion tube 12, it is to be understood that other forms oftactile and non-tactile feedback may be utilized for such purposes. Forexample, in lieu of magnets, a plurality of rings or ridges may beprovided at spaced-apart locations on the first infusion tube 12, andthe distal end of the second drainage tube 14 may be slightly undersizedas compared to other portions of the second drainage tube 14. Thus, asthe rings/ridges pass the undersized portion of the second drainage tube14, the user would sense a slight interference fit, thereby providingfor tactile feedback as the first infusion tube 12 is positionedrelative to second drainage tube 14. Alternatively, instead of therings/ridges being located near the distal end of first infusion tube 12and the tactile feedback being provided by passage through theundersized distal end of the second drainage tube 14, the rings/ridgesmay be provided nearer the proximal end of the first infusion tube 12,with the undersized portion of the second drainage tube 14 also beingprovided at or near a proximal end thereof. With this configuration,direct blood flow over the rings/ridges on first infusion tube 12 may beavoided.

Referring still to FIG. 4, the distal end portion 42 of second drainagetube 14, illustrated as a tapered section, is configured to allow thefirst infusion tube 12 to move axially with respect to second drainagetube 14. In order to prevent blood flow through this tapered section,the distal end portion 42 may include one or more valves (e.g., O-rings)to substantially seal the interface between the first infusion tube 12and the second drainage tube 14. Additionally, the one or more valves atthe distal end portion 42 may function as supplemental securementdevices in order to secure the first infusion tube 12 relative to thesecond drainage tube 14.

Having described several non-limiting embodiments of the coaxial cannula10 and the Y-shaped connector assembly 22, an exemplary and non-limitingmethod for supporting the right heart of a patient using the coaxialcannula 10 will now be described with reference to FIGS. 5 and 6. Inuse, the coaxial cannula 10 is inserted into the pulmonary artery in apercutaneous procedure. Initially, a percutaneous entry needle (notshown) is used to access the patient's internal jugular vein (IJV). Anintroducer, such as a guidewire, is then inserted through the needleuntil the tip of the introducer is positioned in the upper portion ofthe inferior vena cava/right atrium (IVC/RA) junction. The needle canthen be removed, and a pulmonary wedge catheter can be inserted over theguidewire into the pulmonary artery. The introducer tip is then threadedinto the pulmonary artery, and the wedge catheter is removed. The IJV isthen serially dilated and the coaxial cannula 10 is threaded along theintroducer into the IJV, through the right ventricle, and into thepulmonary artery. The distal end 32 of the first infusion tube 12 issufficiently flexible about the central axis 16 so as to navigate theIJV, right ventricle, and pulmonary artery. The coaxial cannula 10 mayinclude insertion depth markers and radiopaque markers for aiding theuser in placing the coaxial cannula 10 in the right atrium. Furthermore,as described above, the position of the first infusion tube 12 relativeto the second drainage tube 14 may be adjusted by the user based on,e.g., patient size, patient vessel length, etc. Once the position of thecoaxial cannula 10 is acceptable, the introducer may be removed and thecoaxial cannula 10 may be clamped in place. For example, the coaxialcannula 10 may be secured to the patient's neck using a suture. FIG. 6shows the coaxial cannula 10 positioned in the patient according to someembodiments of the disclosure. In particular, the distal end 42 of thesecond drainage tube 14 is positioned at least within proximity with theright atrium 64, while the distal end 32 of the first infusion tube 12extends into the pulmonary artery 62.

While several embodiments of a coaxial cannula and connector assemblyare shown in the accompanying figures and described hereinabove indetail, other embodiments will be apparent to, and readily made by,those skilled in the art without departing from the scope and spirit ofthe invention. For example, it is to be understood that this disclosurecontemplates, to the extent possible, that one or more features of anyembodiment can be combined with one or more features of any otherembodiment. Accordingly, the foregoing description is intended to beillustrative rather than restrictive.

What is claimed is:
 1. A dual lumen coaxial cannula assembly comprising:a first infusion tube having a first elongate body defining a firstlumen therethrough, the first infusion tube having a proximal end, adistal end, and a sidewall extending circumferentially therebetween; asecond drainage tube co-axially aligned with the first infusion tube andhaving a second elongate body with a second lumen defined by a spacebetween the first infusion tube and second drainage tube, the seconddrainage tube having a proximal end, a distal end, and a sidewallextending circumferentially therebetween; and a connector assembly,wherein the connector assembly comprises an inlet portion through whicha portion of the first infusion tube is configured to extend and outletportion through which a portion of the second drainage tube isconfigured to extend, wherein the connector assembly is configured toenable selective axial displacement of the first infusion tube throughthe second drainage tube.
 2. The dual lumen coaxial cannula assembly ofclaim 1, wherein the connector assembly comprises a first valvepositioned circumferentially around a portion of the first infusion tubeto secure the first infusion tube relative to the connector assembly. 3.The dual lumen coaxial cannula assembly of claim 2, wherein the firstvalve is configured as a passive valve.
 4. The dual lumen coaxialcannula assembly of claim 3, wherein the first valve is an O-ring. 5.The dual lumen coaxial cannula assembly of claim 2, wherein theconnector assembly comprises a second valve positioned circumferentiallyaround another portion of the first infusion tube to secure the firstinfusion tube relative to the connector assembly.
 6. The dual lumencoaxial cannula assembly of claim 5, wherein the second valve isconfigured as an active valve.
 7. The dual lumen coaxial cannulaassembly of claim 6, wherein the second valve is a Tuohy-Borst valve. 8.The dual lumen coaxial cannula assembly of claim 5, wherein the secondvalve comprises at least one sensor configured to provide feedbackregarding the securement of the first infusion tube relative to thesecond valve.
 9. The dual lumen coaxial cannula assembly of claim 8,wherein the at least one sensor comprises at least one of a pressuretransducer and an axial force strain gauge.
 10. The dual lumen coaxialcannula assembly of claim 5, further comprising a side-port connectionpositioned between the first valve and the second valve of the connectorassembly.
 11. The dual lumen coaxial assembly of claim 5, furthercomprising an embolic protection device positioned between the firstvalve and the second valve of the connector assembly.
 12. The dual lumencoaxial assembly of claim 1, wherein the first infusion tube comprisesat least a first magnet of a first polarity and a second magnet of thefirst polarity positioned along the first elongate body, and furtherwherein the second drainage tube comprises a third magnet of a secondpolarity positioned proximate to a distal end thereof.
 13. The duallumen coaxial assembly of claim 12, wherein the first magnet ispositioned to represent a distal length limit of the first infusion tubeand the second magnet is positioned to represent a proximal length limitof the first infusion tube.
 14. The dual lumen coaxial assembly of claim12, further comprising at least one intermediate magnet positionedbetween the first magnet and the second magnet on the first infusiontube.
 15. The dual lumen coaxial cannula assembly of claim 1, whereinthe first infusion tube includes a plurality of infusion aperturesprovided at the distal end, the infusion apertures extending through thesidewall of the first infusion tube.
 16. The dual lumen coaxial cannulaassembly of claim 1, wherein the second drainage tube includes aplurality of drainage apertures provided at the distal end, the drainageapertures extending through the sidewall of the second drainage tube.17. A method of assisting a patient's heart, comprising the steps of:providing a dual lumen coaxial cannula assembly comprising: a firstinfusion tube having a first elongate body defining a first lumentherethrough, the first infusion tube having a proximal end, a distalend, and a sidewall extending circumferentially therebetween, a seconddrainage tube co-axially aligned with the first infusion tube and havinga second elongate body with a second lumen defined by a space betweenthe first infusion tube and second drainage tube, the second drainagetube having a proximal end, a distal end, and a sidewall extendingcircumferentially therebetween, and a connector assembly, wherein theconnector assembly comprises an inlet portion through which a portion ofthe first infusion tube is configured to extend and outlet portionthrough which a portion of the second drainage tube is configured toextend, wherein the connector assembly is configured to enable selectiveaxial displacement of the first infusion tube through the seconddrainage tube; inserting the dual lumen coaxial cannula into an internaljugular vein of the patient, the dual lumen coaxial cannula having alength to extend from the patient's neck area to the patient's heart;maneuvering the dual lumen coaxial cannula through the patient'svasculature such that the first distal end of the first infusion tube isat least within proximity of the patient's pulmonary artery and suchthat the second distal end of the second drainage tube is at leastwithin proximity of the patient's right atrium; adjusting an axialposition of the first distal end of the first infusion tube relative tothe second distal end of the second drainage tube; securing the firstinfusion tube in a selected axial position relative to the seconddrainage tube; and connecting the dual lumen coaxial cannula to a bloodpump for establishing right ventricular support.
 18. The method of claim17, wherein securing the first infusion tube in the selected axialposition comprises tightening a valve around a portion of the firstinfusion tube, wherein the valve is positioned on the connectorassembly.
 19. The method of claim 17, further comprising providing atleast a first magnet of a first polarity and a second magnet of thefirst polarity along the first elongate body of the first infusion tube,and providing a third magnet of a second polarity proximate to a distalend of the second drainage tube, wherein the first magnet and the secondmagnet provide tactile feedback regarding a position of the firstinfusion tube relative to the third magnet of the second drainage tube.20. The method of claim 17, wherein blood from the blood pump isdelivered to the patient's pulmonary artery through a plurality ofinfusion apertures of the first infusion tube, and further wherein bloodis withdrawn from the patient's right atrium through a plurality ofdrainage apertures of the second drainage cannula.